l3.2.3 Deleting a File.········.············· 394 l3.2.4 Resizing a File.······· 395 13.2.5 Preallocating Space for a File. 395 13.2.6 Querying the Size of a File 396 13.2.7 Querying File Parameters 397 13.2.8 File Info 398 Reserved File Hints 399 l3.3 File Views......。·.·.·. 401 l3.4 Data Access···: 404 13.4.1 Data Access Routines 。。 404 Positioning 405 Synchronism········· 405 Coordination..·.····· 405 Data Access Conventions 406 13.4.2 Data Access with Explicit Offsets... 407 13.4.3 Data Access with Individual File Pointers 410 l3.4.4 Data Access with Shared File Pointers.·.·····.. 416 Noncollective Operations 417 Collective Operations.....·..·. 419 Seek..· 420 13.4.5 Split Collective Data Access Routines 421 l3.5 File Interoperability....·..········ 428 13.5.1 Datatypes for File Interoperability 430 13.5.2 External Data Representation:"external32' 431 13.5.3 User-Defined Data Representations..... 432 Extent Callback 434 Datarep Conversion Functions 435 13.5.4 Matching Data Representations.. 437 13.6 Consistency and Semantics 437 13.6.1 File Consistency···· 437 13.6.2 Random Access vs.Sequential Files 440 13.6.3Pr0gss.··。·.····················· 441 l3.6.4 Collective File Operations..··..··..········ 441 l3.6.5 Type Matching...................·... 441 13.6.6 Miscellaneous Clarifications................ 441 13.6.7 MPl_Offset Type......... 。 442 l3.6.8 Logical vs.Physical File Layout.············ 442 13.6.9 File Size................··.·· 442 13.6.10 Examples .. 443 Asynchronous I/O 445 l3.7I/0 Error Handling..·..······ 447 l3.8I/O Error Classes......·..·· 447 13.9 Examples.... 448 13.9.1 Double Buffering with Split Collective I/O 448 l3.9.2 Subarray Filetype Constructor··..·.. 450 xi13.2.3 Deleting a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 13.2.4 Resizing a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 13.2.5 Preallocating Space for a File . . . . . . . . . . . . . . . . . . . . . . 395 13.2.6 Querying the Size of a File . . . . . . . . . . . . . . . . . . . . . . . 396 13.2.7 Querying File Parameters . . . . . . . . . . . . . . . . . . . . . . . . 397 13.2.8 File Info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 Reserved File Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 13.3 File Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401 13.4 Data Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404 13.4.1 Data Access Routines . . . . . . . . . . . . . . . . . . . . . . . . . . 404 Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 Synchronism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 Coordination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 Data Access Conventions . . . . . . . . . . . . . . . . . . . . . . . . 406 13.4.2 Data Access with Explicit Offsets . . . . . . . . . . . . . . . . . . . . 407 13.4.3 Data Access with Individual File Pointers . . . . . . . . . . . . . . . 410 13.4.4 Data Access with Shared File Pointers . . . . . . . . . . . . . . . . . 416 Noncollective Operations . . . . . . . . . . . . . . . . . . . . . . . . 417 Collective Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 419 Seek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420 13.4.5 Split Collective Data Access Routines . . . . . . . . . . . . . . . . . 421 13.5 File Interoperability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 13.5.1 Datatypes for File Interoperability . . . . . . . . . . . . . . . . . . . 430 13.5.2 External Data Representation: “external32” . . . . . . . . . . . . . . 431 13.5.3 User-Defined Data Representations . . . . . . . . . . . . . . . . . . . 432 Extent Callback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 Datarep Conversion Functions . . . . . . . . . . . . . . . . . . . . . 435 13.5.4 Matching Data Representations . . . . . . . . . . . . . . . . . . . . . 437 13.6 Consistency and Semantics . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 13.6.1 File Consistency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 13.6.2 Random Access vs. Sequential Files . . . . . . . . . . . . . . . . . . 440 13.6.3 Progress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441 13.6.4 Collective File Operations . . . . . . . . . . . . . . . . . . . . . . . . 441 13.6.5 Type Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441 13.6.6 Miscellaneous Clarifications . . . . . . . . . . . . . . . . . . . . . . . 441 13.6.7 MPI_Offset Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442 13.6.8 Logical vs. Physical File Layout . . . . . . . . . . . . . . . . . . . . . 442 13.6.9 File Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442 13.6.10 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 443 Asynchronous I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445 13.7 I/O Error Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 13.8 I/O Error Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 13.9 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448 13.9.1 Double Buffering with Split Collective I/O . . . . . . . . . . . . . . 448 13.9.2 Subarray Filetype Constructor . . . . . . . . . . . . . . . . . . . . . 450 xi